Conventional children's tricycles are steered by turning handlebars attached to a front fork which supports the front wheel of the vehicle. Usually there is no provision for limiting the degree to which the front wheel can be turned. Therefore, if the tricycle is moving forwardly at a relatively high rate of speed and the front wheel is oversteered to the right or left, the forward momentum of the tricycle and its rider may cause the toy to tip over, resulting in possible injury to the rider.
Indeed, in the case of some tricycles, the front fork and handlebars may have unlimited rotary freedom so that they can actually face backwards relative to the remainder of the trike which can be confusing and annoying particularly to very young children just learning to ride.
Also, industry standards covering children's tricycles require that the tricycle steering assembly pass a rotational torque test of at least 35 lbs. This means that with the front fork held in a fixed position, a torque on the handlebars of 35 lbs. must not cause the handlebars to turn relative to the front fork; see U.S. Pat. No. 3,955,828.
It has been proposed to provide some kind of stop for limiting the rotational movements of the front fork and handlebars of tricycles. However, there has been some difficulty accomplishing this objective and still satisfying the above torque requirement while avoiding unduly increasing the overall cost of the tricycle. Some obvious solutions require the use of relatively expensive machined parts. Others necessitate the use of parts which must be spot welded or otherwise held in place prior to assembling the tricycle, thereby increasing labor costs. Still other solutions make it more difficult to assemble the front end of the tricycle. Bearing in mind that most tricycles of this type are shipped to the customer in a knocked-down condition and must be assembled by the parent in the home without any special tools or equipment, it is imperative that the construction be such that the tricycles can be put together by an unskilled person with a minimum amount of time and effort.